The No.8-seeded Stosur battled almost two and a half hours and was up an early break in the third set but ended up falling to Goerges, 76(2) 46 75, her serve particularly troublesome - she hit 14 double faults during the match.

Goerges' serve was no trouble whatsoever though, producing eight aces to just four doubles, and she was a model of focus on break points too - she won three of her six break points and saved 10 of the 13 break points against her.

"I knew I had to be aggressive against Sam - if you stay aggressive you will get your chances, but you have to play for it every point," Goerges said. "I'm pretty pleased with my performance so far this week and hopefully I can keep it up."

Goerges scored her ninth Top 10 win, three of those coming against Stosur (also beating the Australian at Tokyo in 2010 and Stuttgart in 2011).

The No.10-seeded Wozniacki was given all she could handle from Hsieh, unable to hit through the Taiwanese's spins and angles for most of the match - she actually trailed a set and 3-0 at one point, even facing points for a 4-0 deficit in the second set, but she kept fighting and scraped by, 67(5) 76(3) 60.

"It's always tough playing a player from the home country, especially here when the crowd is really excited and cheering for their players," Radwanska said. "When I go on court I prepare for that. And I was happy because I had some Chinese fans out there as well - it wasn't all of them against me today."

Zhang led 3-1 in the second set when Radwanska won five games in a row to close it out. "I'm very happy I could come back in the second set and close that match in straight sets, because every match is tough and here you are playing almost every day," Radwanska said. "She's a very talented player, moving and hitting the ball very well - if she works hard for sure she can be a top player."

Kerber needed just an hour and six minutes to beat Spanish qualifier Lara Arruabarrena-Vecino, 62 60, and later on in the day Azarenka scored a comfortable 64 62 victory against another German giant-killer, Sabine Lisicki.

"Sabine is a very dangerous opponent, so it was important to try to be focused right from the beginning and not let her get into the game," Azarenka said. "She's the kind of player who doesn't give you rhythm and likes to take control, so I had to take control myself. I felt like I was maintaining a very high level."